a=[0,4i];
subplot(2,2,1)
axis equal
plot(a)
for k=1:3
    subplot(2,2,k+1)
    a1=a/4;
    a=[a1,a1*1i+1i,a1+1i-1,a1*(-1i)+2i-1,a1*(-1i)+2i,a1+2i+1,a1*1i+3i+1,a1+3i];
    plot(a)
    axis equal
end